Get Current Week Start & End Date by JavaScript / Jquery

Simple pic of code for JavaScript
<script type="text/javascript">
        $(document).ready(function () {
        var curr = new Date;                               // get current date
        var first = curr.getDate() - curr.getDay(); // First day is the day of the month - the day of the week
        var last = first + 6;                                  // last day is the first day + 6

        var firstday = new Date(curr.setDate(first)).toUTCString();
        var lastday = new Date(curr.setDate(last)).toUTCString();

        $('#startDate').datebox('setValue', firstday);    // I use Easyui Thatswhy my code is different :)
        });
    </script>

and also u can do some formation by like bellow :

var fdate = firstday.getMonth()+1 + "/" + firstday.getDate() + "/" + firstday.getFullYear();